Digital Cables
TT wrote:
"Serge Auckland"
wrote in message ...
:
: I don't think that anybody that knows how digital audio is
transmitted
: would believe that *any* digital cable will make a
difference. AES-EBU
: and SP-DIF signals are incredibly rugged, and provided the
cable is of
: 75 ohms impedance, what it's made of and how constructed
will have *no*
: effect on the signal transmitted.
:
: Balanced AES-EBU signals are even more immune to jitter
caused by
: 50-60Hz hum and are the preferred choice for long cable
runs.
:
:
: S.
:
Isn't AES/EBU digital cable 110Ohm?
Regards TT
AES-EBU or AES-3 as the standard is known can be either 110 ohms
balanced or 75 ohms unbalanced. The signal format is identical, and is
also interchangeable with SP-DIF. The differences are in the settings of
one or more data bits which identify the signal, and in the nominal
signal level. SP-DIF is 0.5v and AES-EBU is 1V,if I remember correctly.
Connectors are normally XLR for balanced AES-EBU, BNC for unbalanced
AES-EBU and phono for SP-DIF
One benefit of using 75 ohm unbalanced AES-EBU is that in a mixed
audio-video facility, all cables are 75 ohms on BNCs, so the same cable
can be used for audio and video.
In an audio-only facility it is better to use all balanced 110 ohm cable
for analogue and digital so again, any balanced cable can be used for
either. The danger comes in older facilities which still have a lot of
balanced non-110 ohm cable, and that gets used for digital audio. As
rugged as AES-EBU is, it doesn't take kindly to long lengths of the
wrong impedance cable.
S.
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